Tom Wood says England are 'building something with substance and sustainability' as they prepare for New Zealand. Photograph: Michael Mayhew/Sportsphoto/Allstar

Sport is about timing as much as talent. The 2013 British & Irish Lions have been rightly feted for their series victory over Australia but would they, under an alternative touring rota, have won in New Zealand?

Which brings us to the defining fixture of England's 2013 at Twickenham. The hosts must pray this year's window of opportunity has not already closed. New Zealand were probably more vulnerable eight days ago, when they narrowly saw off a prolonged French assault in Paris. What price would the bookies be quoting if Alex Corbisiero, Manu Tuilagi, Tom Croft, Marland Yarde and Christian Wade were all fit? Instead Paddy Power has England at 13-2 with the All Blacks 1-9, reflective of the home side's imperfect buildup.

But that's life. If every playing field were as level as a Norfolk ironing board how dull would it be? How is true grit instilled if adversity never intrudes? From AP McCoy to Sachin Tendulkar this is already a month for celebrating those who dig in for the long haul. "There isn't one coward that's ever set foot on a rugby field … it's a battleground," said Andy Farrell, England's backs coach, clearly bang up for the challenge. If his side are to hoist the Webb Ellis Cup in familiar surroundings in 2015, it will be character-forming days such as these that make it possible.

Saturday afternoon's outcome, then, will reveal plenty. Nobody yet knows whether Stuart Lancaster's new England are the real thing, or some other brand of cola. Those who reckon they are overhyped and got lucky a year ago are still out there. If the English lose by 20-odd points it will be seized upon as proof that the Twickenham megastore is flogging the emperor's new clothes.

But here is another possibility before kick-off. What if New Zealand are actually the lucky ones, fortunate to catch England's fledglings now before they soar to a different level? In the 21 months since Lancaster's first game in charge, his team have already climbed from sixth in the IRB world rankings to third. If they win this weekend and Scotland beat South Africa, they will rise to second. Even some of their enemies foresee a seriously bright future.

Take Jimmy Cowan, who won the last of his 51 caps at scrum-half for New Zealand in 2011 before opting to join Gloucester. The 31-year-old sticks out a hand, straightens his fingers and points them upwards like a rocket. "I think England are going like that," he says softly. "That's the scary thing I tell people back home. I think they're the team to be wary of in the World Cup in 2015. There's a lot of untapped talent here that hasn't been touched yet and they've got a lot of good guys coming through. It's not just Gloucester … all the top clubs have some."

This opinion is not yet shared by the International Rugby Players' Association, whose 45-man shortlist for its player of the year award contains just one Englishman, the injured Corbisiero. Despite England's record of nine wins in their past 10 Tests, some will argue it is a fair representation. But then you glance again at the ages of those laying the foundations. Joe Launchbury and Owen Farrell are 22, Courtney Lawes is 24, Billy Vunipola just 21. All of them are potentially 70 cap-plus players who, if they stay fit, could feature for the next three World Cups. The average age of the side that started against Australia was 25 years and 10 days. It was the youngest English side to play a major Test at Twickenham since Clive Woodward's first match as coach in 1997, also against the Wallabies. If they can overcome the world champions now, for the second time inside 12 months, what else might be possible?

Tom Wood, last year's man of the match in the 38-21 win over the All Blacks, already senses the bad old days are history, saying: "I definitely think we are going in the right direction and developing something with a bit more substance and sustainability." Wood, furthermore, reckons England's bedrock of self-belief dates back to 1 December last year, when they stood beneath their own posts having just seen a 15-0 lead reduced to a solitary point. "I honestly think New Zealand felt the same way, that the tide had turned and they were going to run away with the game, as they do most games.

"I saw that drain out of their faces in the last 20 minutes as it went away from them. That is something most of them have not felt before and that'll be at the forefront of their mind when they come out this week. When the pressure comes on we pull tighter."

As the management have been repeatedly stressing, concentration on the basics will also be critical. Watch a rerun of last year's game and what is striking, aside from the sight of All Blacks suffering in the contact area, is the amount of good restart ball England won and the increasing mistakes they forced from normally unflappable operators such as Dan Carter, Conrad Smith and Keven Mealamu.

Can they do it again? Not if they repeat their second-half inaccuracy against Argentina or the first 40 minutes against Australia. New Zealand have also already proved inside the cauldron of Ellis Park that they can cope with any occasion. "If they're at their best we need to be white-hot, don't we?" conceded Farrell. But what if Owen Farrell brings his kicking boots, Dylan Hartley hits endless lineout double tops in his 50th Test and Wood, Launchbury and Lawes soften up the All Blacks forwards?

England are an increasingly tough side to shake off in the final quarter and the referee, Craig Joubert, cannot possibly be as generous to New Zealand as he was in the fateful 2011 World Cup final against France.

Either way, it will be closer than last time. New Zealand must remain favourites by virtue of their 12 straight wins this year. But England are more composed than 12 months ago and 13 is not always the luckiest of numbers. "Because we're a small little island we've always been underdogs and come out fighting," said Farrell, on robust eve-of-game form at a sunny Twickenham. "We're at our best when we have our backs to the wall and when a challenge is laid down to us. That's what we're about. We're a champion team in the making, there's no doubt about that."

A last-gasp winning drop-goal from an English No10, with the peerless Carter looking on, would be a symbolic outcome. Unless, of course, fate has other ideas.